guava cache的数据结构: guava cache的数据结构的构建流程: 1)构建CacheBuilder实例cacheBuilder 2)cacheBuilder实例指定缓存器LocalCache的初始化参数 3)cacheBuilder实例使用build()方法创建LocalCache实例(简单说成这样,实际上复杂一些) 3.1)首先为各个类变量赋值(通过第二步中cacheBuilder指定的初始化参数以及原本就定义好...
The concurrency level option is used to partition the table internally such that updates can occur without contention. The ideal setting would be the maximum number of threads that could potentially access the cache at one time. Here is an example of a possible usage scenario for Guava Cache. ...
guava cache的数据结构: guava cache的数据结构的构建流程: 1)构建CacheBuilder实例cacheBuilder 2)cacheBuilder实例指定缓存器LocalCache的初始化参数 3)cacheBuilder实例使用build()方法创建LocalCache实例(简单说成这样,实际上复杂一些) 3.1)首先为各个类变量赋值(通过第二步中cacheBuilder指定的初始化参数以及原本就定义好...
CacheLoader:有用的部分就是一个load(),用于实现"取缓存-->若不存在,先计算,在缓存-->取缓存"的原子操作 LocalCache:整个guava cache的核心类,包含了guava cache的数据结构以及基本的缓存的操作方法 LocalLoadingCache:LocalCache的一个静态内部类,这里的get(K key)是外部调用get(K key)入口 LoadingCache接口:继承...
import com.google.common.cache.CacheBuilder; import com.google.common.cache.CacheLoader; import com.google.common.cache.LoadingCache; public class GuavaTester { public static void main(String args[]){ //create a cache for employees based on their employee id ...
guava cache是目前最长用的本地缓存,可以把它看成是增加了一些额外功能的ConcurrentHashMap,也是线程安全的本地缓存。 使用示例 @TestpublicvoidtestLoad()throws Exception{LoadingCache<String,Object>loadingCache=CacheBuilder.newBuilder().maximumSize(100).expireAfterWrite(10,TimeUnit.MINUTES).removalListener(notificat...
Cache<String,Obj>cache=CacheBuilder.newBuilder().maximumSize(2).build();Obj obj_a=newObj(1,2);Obj obj_b=newObj(2,2);Obj obj_c=newObj(3,2);// first put count=1cache.put("a",obj_a);Assert.assertEquals(obj_a,cache.getIfPresent("a"));// 2nd put count=2cache.put("b",obj_b...
Of note is that Guava's default concurrency level (4) results in similar performance to a synchronized LinkedHashMap. This is due to the cache's overhead, in particular the GC thrashing from ConcurrentLinkedQueue and a hot read counter. It should also be noted that at the time of developm...
final @Nullable CacheLoader<? super K, V> defaultLoader; /** * Creates a new, empty map with the specified strategy, initial capacity and concurrency level. */ LocalCache( CacheBuilder<? super K, ? super V> builder, @Nullable CacheLoader<? super K, V> loader) { ...
Concurrency Level of the cache (defaults to 4) CacheBuilder被用來建立cache例項(譯註:是指被cache的例項)。它使用fluent style(譯註:就是.xx().xx().xx()的模式)來建立,使你可以指定cache的下列的屬性: Cache大小限制('移除'是使用LRU演算法)